Chem. Pharm. Bull. 56(1) 89-92 (2008)

ery of biologically active compounds from fungi, we have initiated the chemical study of the Japanese lichen, Cladonia rangiferina (L.) WEB. (Cladoniaceae). The lichen, C. rangiferina, is widely distributed in southern Japan and which grows on the ground and rocks from high mountains to low lands. An earlier chemical constituent study of this lichen resulted in no report of the isolation and the biological activity. In our investigation, two new abietane diterpenoids, called hanagokenols A (1), and B (2), along with 15 known compounds including abietane, labdane, isopimarane diterpenoids, monocyclic aromatic compound, depside, and dibenzofuran were isolated from C. rangiferina. We describe here the isolation, purification, and structural elucidation of the unique abietane diterpenes, 1 and 2, primarily by extensive NMR experiments, and the antimicrobial activities of all the isolated compounds against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE). C. rangiferina was milled and exhaustively extracted with AcOEt at room temperature for 8 weeks. The AcOEt extract was fractionated into seven fractions by column chromatography (silica gel), followed by repeated separations of their seven portions by chromatography over silica gel. Reversed-phase silica gel furnished hanagokenols A (1), and B (2), obtuanhydride (3), sugiol (4), 5,6-dehydrosugiol(5), montbretol (6), cis-communic acid (7), imbricatoloic acid (8), 15-acetylimbricatoloic acid (9), junicedric acid (10), 7a-hydroxysandaracopimaric acid (11), b-resorylic acid (12), atranol (13), barbatic acid (14), homosekikaic acid (15), didymic acid (16), and condidymic acid (17). Hanagokenol A (1), [a]D 185.9°, was obtained as an amorphous solid and was considered to have the molecular formula of C20H26O3 based on the high-resolution electron ion mass spectrum (HR-EI-MS) of the molecular ion at m/z 314.1864. The IR spectrum of 1 showed absorption bands at 3370 (OH), 1690 (C O), and 1610 (aromatic) cm . The presence of an aromatic ring was supported by the UV data (lmax 217, 236 and 288 nm). The 20 carbon signals observed in the C-NMR spectrum and distortionless enhancement by polarization transfer (DEPT) experiment (Table 1) revealed the presence of a ketone at d 195.7 (s); a benzene ring at d 111.3 (d), 124.0 (s), 127.3 (d), 134.8 (s), 155.3 (s), and 161.5 (s); two oxygenated carbons at d 77.1 (d), and 84.1 (t), which requires that 1 should contain four rings. The H-NMR specJanuary 2008 89